A High-Speed and High-Yield Path-Switching Sensing Circuit for STT-MRAM

Spin-transfer torque magnetic random access memory (STT-MRAM) is a promising storage technology due to its low power consumption, great scalability, and high endurance. However, with the downscaling of the technology node, the process variation of the device increases fast, leading to increased read failures and read disturbance in STT-MRAM. Moreover, as STT-MRAM is usually considered as an energy-efficient device for low-power designs, the overscaling of supply voltage further degrades the read yield and read latency. In this article, a novel sensing circuit is proposed to improve read yield and read speed by utilizing a path-switching approach. The simulation results demonstrate a sensing latency of 400 ps at a supply voltage of 1 V, with a read yield of 99.9%. Moreover, the proposed circuit exhibits no degradation in read yield at 100 °C or with the supply voltage as low as 0.6 V, demonstrating high reliability.